A request smuggling vulnerability exists in libsoup's HTTP/1 header parsing logic. The soup_message_headers_append_common() function in libsoup/soup-message-headers.c unconditionally appends each header value without validating for duplicate or conflicting Content-Length fields. This allows an attacker to send HTTP requests containing multiple Content-Length headers with differing values.
Fix
Patch, vendor advisory and mitigation references on NVD 3
- https://access.redhat.com/security/cve/CVE-2026-2708 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2440743 Issue Tracking, Vendor Advisory
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/500 Exploit, Issue Tracking, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 5.3 · gnome, redhatNVD modified 2026-10-26 21:10
Affected (CPE criteria) 6
cpe:2.3:a:gnome:libsoup:-:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*
References 4
- https://access.redhat.com/security/cve/CVE-2026-2708 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2440743 Issue Tracking, Vendor Advisory
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/500 Exploit, Issue Tracking, Vendor Advisory
- https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/513 Issue Tracking